data/src/main/scala/storage/elasticsearch/ESUtils.scala

/** Copyright 2014 TappingStone, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

package io.prediction.data.storage.elasticsearch

import org.elasticsearch.action.search.SearchRequestBuilder
import org.elasticsearch.action.search.SearchResponse
import org.elasticsearch.client.Client
import org.elasticsearch.common.unit.TimeValue
import org.json4s.Formats
import org.json4s.native.Serialization.read

import scala.collection.mutable.ArrayBuffer

object ESUtils {
  val scrollLife = new TimeValue(60000)

  def getAll[T : Manifest](
      client: Client,
      builder: SearchRequestBuilder)(
      implicit formats: Formats): Seq[T] = {
    val results = ArrayBuffer[T]()
    var response = builder.setScroll(scrollLife).get
    var hits = response.getHits().hits()
    results ++= hits.map(h => read[T](h.getSourceAsString))
    while (hits.size > 0) {
      response = client.prepareSearchScroll(response.getScrollId).
        setScroll(scrollLife).get
      hits = response.getHits().hits()
      results ++= hits.map(h => read[T](h.getSourceAsString))
    }
    results
  }
}